Prior to the delivery of many products to consumers, poultry commonly is divided mechanically into several components attractive for consumers, or practical for further processing or inclusion in other food products. Accordingly, it is an increasingly common procedure to remove the bone from certain pieces of poultry, again either for enhanced consumer appeal or inclusion in other food products. It is desirable that this bone removal process obtain a high efficiency separation of meat from bone, while maintaining a high quality fillet. Although many efforts have been made in this field for mechanically separating bone and flesh, the results until now are often less satisfactory than hand-work.
Conventional techniques for manual deboning require using a knife to make an initial longitudinal slit through meat followed by a latterly outward tearing motion with the hands. Whereas hand-work provides high quality fillets and enables a highly efficient removal of flesh from bone, the hand-work is labor intensive and expensive. Also, the working conditions are detrimental to the health and safety of the operators, and even hinder the quality of meat obtained. Since the working conditions include a refrigerated environment and the use of knives, the concern for worker safety mandates that the operators wear heavy, protective, steel mesh gloves, which diminish the tactile sensitivity of the operators, and work quality suffers. Removal of the gloves to enhance work quality necessarily entails risk of injury through exposure to cold and to cutting blades.
In contrast to the manual removal of the bone which leads to high quality deboned fillet pieces at a relatively high labor expense, the automatic removal with the known machines has many disadvantages and a small gain.
Mechanical deboning apparatus are know in the patent literature, but no widely used in the industry. U.S. Pat. Nos. 5,090,940, 4,882,810 and 3,510,908 disclose devices for separating the meat from certain types of bones of animals, such as poultry leg bones or ungulate leg bones and the like. These known devices generally apply opposing forces to the flesh and to the bone components of the piece to be deboned. In some devices, the strategy employed is to fix the meat component, and then to physically grasp and pull out the bone. Other known devices utilize a strategy of physically grasping the bone, and then using a separate component such as a rigid or semi-rigid orifice, or blades biased against the bone to scrape or strip the flesh away from the bone.
In all these known devices, the bone is physically grasped by some component of the device. In some cases, this is done to keep the bone from moving with the flesh as the device strips the meat away from the fixed bone. In other devices, the grasped bone is subsequently pulled away from the further immobilized meat component. This introduces a further difficulty presented by these devices, in that often a deteriorated fillet is obtained, and the joint connective tissue thereof remains connected to the fillet. Therefore, the joint connective tissue has be removed in a separate operation step.
U.S. Pat. No. 4,380,849 discloses an apparatus for removing the meat from poultry drum sticks. In this device, components are variously arrayed to grasp the small end of a turkey drum stick bone, hold the flesh component of the drum stick, and score the drum stick about the base of the small end with rotating knives in order to loosen the meat from the tendons, gristle, and the other slender elongated cartilage tissues found at the lower end of the poultry drum sticks. Finally, the bone is pulled away from the immobilized meat. A disadvantage of this known device is that the rotating knife mechanism is relatively complex, with multiple moving parts each subject to malfunction. Moreover, the fillet is pulled inside out during the stripping process and must be returned to its natural state if sold directly to consumers.
Automatically separating raw flesh or meat from a piece of meat having an elongated bone with a knuckle or enlarged ends, therefore, poses certain distinct problems. However, once removed, the meat can be cooked or processed alone while avoiding the inefficiency of cooking or further processing the bone. Also, the separated bone can be processed further to make bone meal or other byproducts.
Accordingly, it is the object of the invention to provide an apparatus and method for separating meat from a bone of a poultry limb or the like by which high quality fillets can be obtained which are fee from non-meat particles, and where a minimum of non-usable meat remains attached to the bone.
It is a further object of the present invention to provide a method and apparatus for producing high quality fillets with the joint and other connective tissue removed from the meat.
A further object of the invention is to provide a method and apparatus wherein a high quality fillet is efficiently separated from an elongated bone, with an apparatus having a minimum of moving parts, increased durability and a lower maintenance requirement.
It is still a further object of the present invention to provide a method and apparatus for separating a high quality fillet from an elongated bone with enlarged end portions which provides greatly enhanced safety for operating personnel.
The apparatus and method of the present invention has other objects and features of advantage which will become apparent from and are set forth in more detail in the description of the Best Mode of Carrying Out the Invention and the accompanying drawing.